- Czech Prime Minister said Thursday the staff numbers were "historically disproportionate".
PRAGUE: The Czech Republic was expected to announce the expulsion of more Russian diplomats on Thursday after Moscow rejected as "unacceptable" an ultimatum from Prague.
Prague asked Moscow on Wednesday to allow 20 Czech diplomats who were expelled in a retaliatory move to return to work by noon (1000 GMT) on Thursday.
The Czech Republic had earlier expelled 18 Russian diplomats seen as spies over the suspected involvement of Russian secret services in a 2014 explosion that killed two people in Czech Republic.
Czech Foreign Minister Jakub Kulhanek said Wednesday the Russian embassy staff should correspond to the workforce at the Czech embassy in Moscow which now employs a mere five diplomats and 19 other staff.
Czech Prime Minister Andrej Babis said Thursday the staff numbers were "historically disproportionate".
"I guess we need to draw a thick line, adjust the diplomat numbers and then we'll see. I hope our allies will support us," Babis told reporters.
The European Union voiced support on Wednesday and NATO followed suit in a statement Thursday, expressing "deep concern over the destabilising actions Russia continues to carry out across the Euro-Atlantic area."
Moscow, which currently has 27 diplomats and 67 other staff at its Prague embassy, said Wednesday the ultimatum was "unacceptable".
Prague on Saturday accused the Russian foreign intelligence service of being behind an explosion at an ammunition depot near the eastern village of Vrbetice in 2014 that killed two Czech nationals.
Czech police are seeking two men in connection with that blast, as well as a second, non-fatal explosion nearby later the same year.
Britain has identified the same men as suspects in the 2018 poisoning of former Russian double agent Sergei Skripal in Salisbury, England.
The Czech attack allegedly targeted ammunition belonging to a Bulgarian arms dealer. Media reports have suggested he had been exporting arms to Ukraine, although he has denied this.
The explosion occurred the same year that Russia annexed the Crimean peninsula from Ukraine and a conflict broke out between Ukrainian forces and Russia-backed rebels in the east of the country.